The present invention relates to universal joints, and more particularly to universal joints which are termed "ball joints" and which are suitable for use in vehicle steering mechanisms for interconnecting the input shaft and the output shaft.
Such universal joints heretofore known include those comprising two metal yokes and a ball joint member of synthetic resin interconnecting the yokes (see Unexamined Japanese Utility Model Publication SHO 59-122430). The ball joint member is divided into a half segment toward one of the yokes and another half segment toward the other yoke and has a spring for preventing the divided segments from backlashing relative to each other.
With such conventional universal joints, however, the spring is projected outward beyond the ball joint member in contact with the yokes, so that the spring or the yokes undergo marked wear, which renders the spring inoperative within a relatively short period of time, permitting backlashing. Moreover, the spring is cumbersome to install when the ball joint member is assembled.
When the universal joint is used for some vehicle steering mechanism or the like, there arises a need to pass current across the two yokes. Nevertheless, with the conventional universal joint of the type described, power is transmitted from one yoke to the other through the ball joint member of synthetic resin with the two yokes held out of direct contact with each other. Accordingly, it is impossible to pass current across the two yokes thus arranged.